1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus. In particular, the invention is useful for a liquid ejecting head and a liquid ejecting apparatus when the invention is applied to a system in which liquids are ejected by driving piezoelectric devices of a longitudinal vibration type.
2. Related Art
As a representative example of liquid ejecting heads, there is known an ink jet recording head which discharges ink droplets from nozzle openings using pressure caused by displacement of piezoelectric devices, for example. As a type of such ink jet recording head, there is an ink jet recording head in which piezoelectric devices (piezoelectric vibrators) are longitudinally provided on a region opposed to pressure generating chambers, which communicate with nozzle openings, through a vibration plate (for example, see JP-A-2004-74740). In the ink jet recording head, ink droplets are discharged from the nozzle openings by causing the pressure generating chambers to expand and contract by utilizing longitudinal vibration of the piezoelectric devices. The longitudinal vibration is generated by applying voltage to the piezoelectric devices. The piezoelectric devices of such ink jet recording head are accommodated in accommodating portions of a head case (base), and are electrically connected to conductive pads on a wiring substrate (upper-side sealing plate) provided on the head case through a circuit substrate which is typically formed with an FPC or the like. That is to say, an output terminal that is one end of the circuit substrate is connected to the piezoelectric devices, while an input terminal that is the other end of the circuit substrate is connected to the conductive pads on the wiring substrate. Thus, a driving signal for driving each piezoelectric device is supplied to each piezoelectric device through the input terminal of the circuit substrate.
As an example of the ink jet recording head utilizing longitudinal vibration as described above, there is proposed an ink jet recording head having a configuration as follows (for example, see JP-A-2000-218774, p. 3, FIGS. 4 and 7). That is, one piezoelectric device unit is formed by fixing a number of piezoelectric devices, which are integrated, to a side face of a fixing member, and two piezoelectric device units are paired to be accommodated in an accommodating portion of a head holder to be disposed on the side faces of the head holder.
Reductions in size and the number of components are desired in the above-described ink jet recording head utilizing longitudinal vibration.
Note that reductions in size and the number of components are desired not only in the ink jet recording head which discharges inks but also in liquid ejecting heads which eject liquids other than inks.
An advantage of some aspects of the invention is to provide a liquid ejecting head and a liquid ejecting apparatus which are reduced in size and include fewer components.